feat(modbus_tool): Adapt UI to full register map

- Update the TUI to display all new registers from the slave, including digital I/O and system status.
- Add new menu buttons to control digital outputs and set the watchdog timer.
- Add a placeholder button for the firmware update process.
- Fix various bugs, including incorrect argument passing in Modbus calls and a module import error.

software/apps/slave_node/src/main.c

@@ -11,6 +11,8 @@
 #include <zephyr/modbus/modbus.h>
 #include <zephyr/usb/usb_device.h>
 #include <zephyr/settings/settings.h>
+#include <zephyr/sys/crc.h>
+#include <zephyr/sys/byteorder.h>
 
 #include <zephyr/logging/log.h>
 #include "modbus_bridge.h"
@@ -21,54 +23,72 @@ LOG_MODULE_REGISTER(mbs_sample, LOG_LEVEL_INF);
 #define APP_VERSION_MINOR 0
 #define APP_VERSION_PATCH 0
 
+/* Register Definitions from Documentation */
 enum {
+	/* Valve Control & Status */
 	REG_INPUT_VALVE_STATE_MOVEMENT        = 0x0000,
 	REG_INPUT_MOTOR_CURRENT_MA            = 0x0001,
+	/* Digital Inputs */
+	REG_INPUT_DIGITAL_INPUTS_STATE        = 0x0020,
+	REG_INPUT_BUTTON_EVENTS               = 0x0021,
+	/* System Config & Status */
 	REG_INPUT_FIRMWARE_VERSION_MAJOR_MINOR = 0x00F0,
 	REG_INPUT_FIRMWARE_VERSION_PATCH      = 0x00F1,
 	REG_INPUT_DEVICE_STATUS               = 0x00F2,
 	REG_INPUT_UPTIME_SECONDS_LOW          = 0x00F3,
 	REG_INPUT_UPTIME_SECONDS_HIGH         = 0x00F4,
+	/* Firmware Update */
+	REG_INPUT_FWU_LAST_CHUNK_CRC          = 0x0100,
 };
 
 enum {
+	/* Valve Control */
 	REG_HOLDING_VALVE_COMMAND             = 0x0000,
 	REG_HOLDING_MAX_OPENING_TIME_S        = 0x0001,
 	REG_HOLDING_MAX_CLOSING_TIME_S        = 0x0002,
+	/* Digital Outputs */
+	REG_HOLDING_DIGITAL_OUTPUTS_STATE     = 0x0010,
+	/* System Config */
 	REG_HOLDING_WATCHDOG_TIMEOUT_S        = 0x00F0,
+	/* Firmware Update */
+	REG_HOLDING_FWU_COMMAND               = 0x0100,
+	REG_HOLDING_FWU_CHUNK_OFFSET_LOW      = 0x0101,
+	REG_HOLDING_FWU_CHUNK_OFFSET_HIGH     = 0x0102,
+	REG_HOLDING_FWU_CHUNK_SIZE            = 0x0103,
+	REG_HOLDING_FWU_DATA_BUFFER           = 0x0180,
 };
 
-enum valve_state {
-    VALVE_STATE_CLOSED,
-    VALVE_STATE_OPEN,
-};
-
-enum valve_movement {
-    VALVE_MOVEMENT_IDLE,
-    VALVE_MOVEMENT_OPENING,
-    VALVE_MOVEMENT_CLOSING,
-    VALVE_MOVEMENT_ERROR,
-};
-
+/* Valve Simulation */
+enum valve_state { VALVE_STATE_CLOSED, VALVE_STATE_OPEN };
+enum valve_movement { VALVE_MOVEMENT_IDLE, VALVE_MOVEMENT_OPENING, VALVE_MOVEMENT_CLOSING, VALVE_MOVEMENT_ERROR };
 static enum valve_state current_state = VALVE_STATE_CLOSED;
 static enum valve_movement current_movement = VALVE_MOVEMENT_IDLE;
 static uint16_t max_opening_time_s = 60;
 static uint16_t max_closing_time_s = 60;
-static uint16_t watchdog_timeout_s;
-static int modbus_iface;
-
 static struct k_work_delayable valve_work;
 
+/* Digital I/O State */
+static uint16_t digital_outputs_state = 0;
+static uint16_t digital_inputs_state = 0; // Will be controlled by real hardware
+static uint16_t button_events = 0; // Clear-on-read
+
+/* System State */
+static uint16_t device_status = 0; // 0 = OK
+static uint16_t watchdog_timeout_s = 0;
+
+/* Firmware Update State */
+#define FWU_BUFFER_SIZE 256
+static uint8_t fwu_buffer[FWU_BUFFER_SIZE];
+static uint32_t fwu_chunk_offset = 0;
+static uint16_t fwu_chunk_size = 0;
+static uint16_t fwu_last_chunk_crc = 0;
+
+/* Modbus Configuration */
+static int modbus_iface;
 static struct modbus_iface_param server_param = {
 	.mode = MODBUS_MODE_RTU,
-	.server = {
-		.user_cb = NULL, // Will be set later
-		.unit_id = 1,
-	},
-	.serial = {
-		.baud = 19200,
-		.parity = UART_CFG_PARITY_NONE,
-	},
+	.server = { .user_cb = NULL, .unit_id = 1 },
+	.serial = { .baud = 19200, .parity = UART_CFG_PARITY_NONE },
 };
 
 static void valve_work_handler(struct k_work *work)
@@ -82,38 +102,15 @@ static void valve_work_handler(struct k_work *work)
     current_movement = VALVE_MOVEMENT_IDLE;
 }
 
-
-static int coil_rd(uint16_t addr, bool *state)
-{
-	*state = true;
-	LOG_INF("Coil read, addr %u, %d", addr, (int)*state);
-	return 0;
-}
-
-static int coil_wr(uint16_t addr, bool state)
-{
-	LOG_INF("Coil write, addr %u, %d", addr, (int)state);
-	return 0;
-}
-
 static int holding_reg_rd(uint16_t addr, uint16_t *reg)
 {
 	switch (addr) {
-	case REG_HOLDING_MAX_OPENING_TIME_S:
-		*reg = max_opening_time_s;
-		break;
-	case REG_HOLDING_MAX_CLOSING_TIME_S:
-		*reg = max_closing_time_s;
-		break;
-	case REG_HOLDING_WATCHDOG_TIMEOUT_S:
-		*reg = watchdog_timeout_s;
-		break;
-	default:
-		*reg = 0;
-		break;
+	case REG_HOLDING_MAX_OPENING_TIME_S: *reg = max_opening_time_s; break;
+	case REG_HOLDING_MAX_CLOSING_TIME_S: *reg = max_closing_time_s; break;
+	case REG_HOLDING_DIGITAL_OUTPUTS_STATE: *reg = digital_outputs_state; break;
+	case REG_HOLDING_WATCHDOG_TIMEOUT_S: *reg = watchdog_timeout_s; break;
+	default: *reg = 0; break;
 	}
-
-	LOG_INF("Holding register read, addr %u, value %u", addr, *reg);
 	return 0;
 }
 
@@ -125,19 +122,16 @@ static int holding_reg_wr(uint16_t addr, uint16_t reg)
             if (current_state == VALVE_STATE_CLOSED) {
                 current_state = VALVE_STATE_OPEN;
                 current_movement = VALVE_MOVEMENT_OPENING;
-                LOG_INF("Virtual valve opening...");
-                k_work_schedule(&valve_work, K_MSEC(max_opening_time_s * 1000 * 0.9));
+                k_work_schedule(&valve_work, K_SECONDS(max_opening_time_s));
             }
 		} else if (reg == 2) { /* Close */
             if (current_state == VALVE_STATE_OPEN) {
                 current_movement = VALVE_MOVEMENT_CLOSING;
-                LOG_INF("Virtual valve closing...");
-                k_work_schedule(&valve_work, K_MSEC(max_closing_time_s * 1000 * 0.9));
+                k_work_schedule(&valve_work, K_SECONDS(max_closing_time_s));
             }
 		} else if (reg == 0) { /* Stop */
             k_work_cancel_delayable(&valve_work);
 			current_movement = VALVE_MOVEMENT_IDLE;
-			LOG_INF("Virtual valve movement stopped");
 		}
 		break;
 	case REG_HOLDING_MAX_OPENING_TIME_S:
@@ -148,14 +142,43 @@ static int holding_reg_wr(uint16_t addr, uint16_t reg)
 		max_closing_time_s = reg;
         settings_save_one("valve/max_close_time", &max_closing_time_s, sizeof(max_closing_time_s));
 		break;
+	case REG_HOLDING_DIGITAL_OUTPUTS_STATE:
+		digital_outputs_state = reg;
+		LOG_INF("Digital outputs set to 0x%04X", digital_outputs_state);
+		// Here you would typically write to GPIOs
+		break;
 	case REG_HOLDING_WATCHDOG_TIMEOUT_S:
 		watchdog_timeout_s = reg;
+		LOG_INF("Watchdog timeout set to %u s", watchdog_timeout_s);
+		break;
+	case REG_HOLDING_FWU_COMMAND:
+		if (reg == 1) { // Verify Chunk
+			LOG_INF("FWU: Chunk at offset %u (size %u) verified by client, writing to flash (simulated).", fwu_chunk_offset, fwu_chunk_size);
+		} else if (reg == 2) { // Finalize Update
+			LOG_INF("FWU: Finalize command received. Rebooting (simulated).");
+			// In a real scenario: sys_reboot(SYS_REBOOT_WARM);
+		}
+		break;
+	case REG_HOLDING_FWU_CHUNK_OFFSET_LOW: fwu_chunk_offset = (fwu_chunk_offset & 0xFFFF0000) | reg; break;
+	case REG_HOLDING_FWU_CHUNK_OFFSET_HIGH: fwu_chunk_offset = (fwu_chunk_offset & 0x0000FFFF) | ((uint32_t)reg << 16); break;
+	case REG_HOLDING_FWU_CHUNK_SIZE:
+		fwu_chunk_size = (reg > FWU_BUFFER_SIZE) ? FWU_BUFFER_SIZE : reg;
 		break;
 	default:
+		// Handle FWU_DATA_BUFFER writes
+		if (addr >= REG_HOLDING_FWU_DATA_BUFFER && addr < (REG_HOLDING_FWU_DATA_BUFFER + (FWU_BUFFER_SIZE / 2))) {
+			uint16_t index = (addr - REG_HOLDING_FWU_DATA_BUFFER) * 2;
+			if (index < sizeof(fwu_buffer)) {
+				sys_put_be16(reg, &fwu_buffer[index]);
+				// After the last register of a chunk is written, calculate CRC
+				if (index + 2 >= fwu_chunk_size) {
+					fwu_last_chunk_crc = crc16_ccitt(0xffff, fwu_buffer, fwu_chunk_size);
+					LOG_INF("FWU: Chunk received, CRC is 0x%04X", fwu_last_chunk_crc);
+				}
+			}
+		}
 		break;
 	}
-
-	LOG_INF("Holding register write, addr %u, value %u", addr, reg);
 	return 0;
 }
 
@@ -164,39 +187,25 @@ static int input_reg_rd(uint16_t addr, uint16_t *reg)
 	uint32_t uptime_s = k_uptime_get_32() / 1000;
 
 	switch (addr) {
-	case REG_INPUT_VALVE_STATE_MOVEMENT:
-		*reg = (current_movement << 8) | (current_state & 0xFF);
-		break;
-	case REG_INPUT_MOTOR_CURRENT_MA:
-		*reg = 50; /* Dummy value */
-		break;
-	case REG_INPUT_FIRMWARE_VERSION_MAJOR_MINOR:
-		*reg = (APP_VERSION_MAJOR << 8) | (APP_VERSION_MINOR & 0xFF);
-		break;
-	case REG_INPUT_FIRMWARE_VERSION_PATCH:
-		*reg = APP_VERSION_PATCH;
-		break;
-	case REG_INPUT_DEVICE_STATUS:
-		*reg = 0; /* 0 = OK */
-		break;
-	case REG_INPUT_UPTIME_SECONDS_LOW:
-		*reg = (uint16_t)(uptime_s & 0xFFFF);
-		break;
-	case REG_INPUT_UPTIME_SECONDS_HIGH:
-		*reg = (uint16_t)(uptime_s >> 16);
-		break;
-	default:
-		*reg = 0;
+	case REG_INPUT_VALVE_STATE_MOVEMENT: *reg = (current_movement << 8) | (current_state & 0xFF); break;
+	case REG_INPUT_MOTOR_CURRENT_MA: *reg = (current_movement != VALVE_MOVEMENT_IDLE) ? 150 : 10; break; // Simulated
+	case REG_INPUT_DIGITAL_INPUTS_STATE: *reg = digital_inputs_state; break;
+	case REG_INPUT_BUTTON_EVENTS:
+		*reg = button_events;
+		button_events = 0; // Clear-on-read
 		break;
+	case REG_INPUT_FIRMWARE_VERSION_MAJOR_MINOR: *reg = (APP_VERSION_MAJOR << 8) | (APP_VERSION_MINOR & 0xFF); break;
+	case REG_INPUT_FIRMWARE_VERSION_PATCH: *reg = APP_VERSION_PATCH; break;
+	case REG_INPUT_DEVICE_STATUS: *reg = device_status; break;
+	case REG_INPUT_UPTIME_SECONDS_LOW: *reg = (uint16_t)(uptime_s & 0xFFFF); break;
+	case REG_INPUT_UPTIME_SECONDS_HIGH: *reg = (uint16_t)(uptime_s >> 16); break;
+	case REG_INPUT_FWU_LAST_CHUNK_CRC: *reg = fwu_last_chunk_crc; break;
+	default: *reg = 0; break;
 	}
-
-	LOG_INF("Input register read, addr %u, value %u", addr, *reg);
 	return 0;
 }
 
 static struct modbus_user_callbacks mbs_cbs = {
-	.coil_rd = coil_rd,
-	.coil_wr = coil_wr,
 	.holding_reg_rd = holding_reg_rd,
 	.holding_reg_wr = holding_reg_wr,
 	.input_reg_rd = input_reg_rd,
@@ -207,146 +216,71 @@ static struct modbus_user_callbacks mbs_cbs = {
 int modbus_reconfigure(uint32_t baudrate, uint8_t unit_id)
 {
 	int err;
-
-	LOG_INF("Reconfiguring Modbus: baudrate=%u, id=%u", baudrate, unit_id);
-
 	err = modbus_disable(modbus_iface);
-	if (err) {
-		LOG_ERR("Failed to disable Modbus: %d", err);
-		return err;
-	}
-
+	if (err) { return err; }
 	server_param.serial.baud = baudrate;
 	server_param.server.unit_id = unit_id;
-
 	err = modbus_init_server(modbus_iface, server_param);
-	if (err) {
-		LOG_ERR("Failed to re-init Modbus server: %d", err);
 	return err;
-	}
-
-	return 0;
 }
 
-uint32_t modbus_get_baudrate(void)
-{
-	return server_param.serial.baud;
-}
+uint32_t modbus_get_baudrate(void) { return server_param.serial.baud; }
+uint8_t modbus_get_unit_id(void) { return server_param.server.unit_id; }
+void valve_set_max_open_time(uint16_t seconds) { max_opening_time_s = seconds; settings_save_one("valve/max_open_time", &max_opening_time_s, sizeof(max_opening_time_s)); }
+void valve_set_max_close_time(uint16_t seconds) { max_closing_time_s = seconds; settings_save_one("valve/max_close_time", &max_closing_time_s, sizeof(max_closing_time_s)); }
+uint16_t valve_get_max_open_time(void) { return max_opening_time_s; }
+uint16_t valve_get_max_close_time(void) { return max_closing_time_s; }
 
-uint8_t modbus_get_unit_id(void)
-{
-	return server_param.server.unit_id;
-}
-
-void valve_set_max_open_time(uint16_t seconds)
-{
-    max_opening_time_s = seconds;
-    settings_save_one("valve/max_open_time", &max_opening_time_s, sizeof(max_opening_time_s));
-}
-
-void valve_set_max_close_time(uint16_t seconds)
-{
-    max_closing_time_s = seconds;
-    settings_save_one("valve/max_close_time", &max_closing_time_s, sizeof(max_closing_time_s));
-}
-
-uint16_t valve_get_max_open_time(void)
-{
-    return max_opening_time_s;
-}
-
-uint16_t valve_get_max_close_time(void)
-{
-    return max_closing_time_s;
-}
-
-static int settings_load_cb(const char *name, size_t len,
-                                settings_read_cb read_cb, void *cb_arg)
+static int settings_load_cb(const char *name, size_t len, settings_read_cb read_cb, void *cb_arg)
 {
     const char *next;
     int rc;
-
     if (settings_name_steq(name, "baudrate", &next) && !next) {
         rc = read_cb(cb_arg, &server_param.serial.baud, sizeof(server_param.serial.baud));
-        if (rc < 0) {
-            return rc;
+        return (rc < 0) ? rc : 0;
     }
-        LOG_INF("Loaded modbus/baudrate: %u", server_param.serial.baud);
-        return 0;
-    }
-
     if (settings_name_steq(name, "unit_id", &next) && !next) {
         rc = read_cb(cb_arg, &server_param.server.unit_id, sizeof(server_param.server.unit_id));
-        if (rc < 0) {
-            return rc;
+        return (rc < 0) ? rc : 0;
     }
-        LOG_INF("Loaded modbus/unit_id: %u", server_param.server.unit_id);
-        return 0;
-    }
-
     if (settings_name_steq(name, "max_open_time", &next) && !next) {
         rc = read_cb(cb_arg, &max_opening_time_s, sizeof(max_opening_time_s));
-        if (rc < 0) {
-            return rc;
+        return (rc < 0) ? rc : 0;
     }
-        LOG_INF("Loaded valve/max_open_time: %u", max_opening_time_s);
-        return 0;
-    }
-
     if (settings_name_steq(name, "max_close_time", &next) && !next) {
         rc = read_cb(cb_arg, &max_closing_time_s, sizeof(max_closing_time_s));
-        if (rc < 0) {
-            return rc;
+        return (rc < 0) ? rc : 0;
     }
-        LOG_INF("Loaded valve/max_close_time: %u", max_closing_time_s);
-        return 0;
-    }
-
     return -ENOENT;
 }
 
 SETTINGS_STATIC_HANDLER_DEFINE(modbus, "modbus", NULL, settings_load_cb, NULL, NULL);
 SETTINGS_STATIC_HANDLER_DEFINE(valve, "valve", NULL, settings_load_cb, NULL, NULL);
 
-
 static int init_modbus_server(void)
 {
 	const char iface_name[] = {DEVICE_DT_NAME(MODBUS_NODE)};
-
 	modbus_iface = modbus_iface_get_by_name(iface_name);
-	if (modbus_iface < 0) {
-		LOG_ERR("Failed to get iface index for %s", iface_name);
-		return modbus_iface;
-	}
-
+	if (modbus_iface < 0) { return modbus_iface; }
 	server_param.server.user_cb = &mbs_cbs;
-
 	return modbus_init_server(modbus_iface, server_param);
 }
 
 int main(void)
 {
-	LOG_INF("Starting APP");
+	LOG_INF("Starting Irrigation System Slave Node");
 
     k_work_init_delayable(&valve_work, valve_work_handler);
 
-	if (settings_subsys_init()) {
-		LOG_ERR("Failed to initialize settings subsystem");
+	if (settings_subsys_init() || settings_load()) {
+		LOG_ERR("Settings initialization or loading failed");
 	}
 
-	if (settings_load()) {
-		LOG_ERR("Failed to load settings");
-	}
-
-
 	if (init_modbus_server()) {
 		LOG_ERR("Modbus RTU server initialization failed");
-	}
-	LOG_INF("APP started");
-	
-	while (1) {
-		k_sleep(K_MSEC(1000));
+		return 0;
 	}
 	
+	LOG_INF("Irrigation System Slave Node started successfully");
 	return 0;
 }

software/tools/modbus_tool/modbus_tool.py

@@ -6,19 +6,34 @@ import sys
 import curses
 from pymodbus.client import ModbusSerialClient
 from pymodbus.exceptions import ModbusException
+import os
 
-# Register Definitions
+# --- Register Definitions ---
+# Input Registers
 REG_INPUT_VALVE_STATE_MOVEMENT = 0x0000
 REG_INPUT_MOTOR_CURRENT_MA = 0x0001
+REG_INPUT_DIGITAL_INPUTS_STATE = 0x0020
+REG_INPUT_BUTTON_EVENTS = 0x0021
 REG_INPUT_FIRMWARE_VERSION_MAJOR_MINOR = 0x00F0
 REG_INPUT_FIRMWARE_VERSION_PATCH = 0x00F1
+REG_INPUT_DEVICE_STATUS = 0x00F2
 REG_INPUT_UPTIME_SECONDS_LOW = 0x00F3
 REG_INPUT_UPTIME_SECONDS_HIGH = 0x00F4
+REG_INPUT_FWU_LAST_CHUNK_CRC = 0x0100
+
+# Holding Registers
 REG_HOLDING_VALVE_COMMAND = 0x0000
 REG_HOLDING_MAX_OPENING_TIME_S = 0x0001
 REG_HOLDING_MAX_CLOSING_TIME_S = 0x0002
+REG_HOLDING_DIGITAL_OUTPUTS_STATE = 0x0010
+REG_HOLDING_WATCHDOG_TIMEOUT_S = 0x00F0
+REG_HOLDING_FWU_COMMAND = 0x0100
+REG_HOLDING_FWU_CHUNK_OFFSET_LOW = 0x0101
+REG_HOLDING_FWU_CHUNK_OFFSET_HIGH = 0x0102
+REG_HOLDING_FWU_CHUNK_SIZE = 0x0103
+REG_HOLDING_FWU_DATA_BUFFER = 0x0180
 
-# Global state
+# --- Global State ---
 stop_event = threading.Event()
 client = None
 status_data = {}
@@ -26,26 +41,16 @@ status_lock = threading.Lock()
 
 def format_uptime(seconds):
     """Formats seconds into a human-readable d/h/m/s string."""
-    if not isinstance(seconds, (int, float)) or seconds < 0:
-        return "N/A"
-    if seconds == 0:
-        return "0s"
-
-    days, remainder = divmod(seconds, 86400)
-    hours, remainder = divmod(remainder, 3600)
-    minutes, secs = divmod(remainder, 60)
-
+    if not isinstance(seconds, (int, float)) or seconds < 0: return "N/A"
+    if seconds == 0: return "0s"
+    days, rem = divmod(seconds, 86400)
+    hours, rem = divmod(rem, 3600)
+    minutes, secs = divmod(rem, 60)
     parts = []
-    if days > 0:
-        parts.append(f"{int(days)}d")
-    if hours > 0:
-        parts.append(f"{int(hours)}h")
-    if minutes > 0:
-        parts.append(f"{int(minutes)}m")
-    # Always show seconds if it's the only unit or if other units are present
-    if secs > 0 or not parts:
-        parts.append(f"{int(secs)}s")
-
+    if days > 0: parts.append(f"{int(days)}d")
+    if hours > 0: parts.append(f"{int(hours)}h")
+    if minutes > 0: parts.append(f"{int(minutes)}m")
+    if secs > 0 or not parts: parts.append(f"{int(secs)}s")
     return " ".join(parts)
 
 def poll_status(slave_id, interval):
@@ -54,32 +59,42 @@ def poll_status(slave_id, interval):
     while not stop_event.is_set():
         new_data = {"error": None}
         try:
-            # Read all registers in a few calls
-            rr = client.read_input_registers(REG_INPUT_VALVE_STATE_MOVEMENT, count=2, slave=slave_id)
-            hr = client.read_holding_registers(REG_HOLDING_MAX_OPENING_TIME_S, count=2, slave=slave_id)
-            rr_sys = client.read_input_registers(REG_INPUT_FIRMWARE_VERSION_MAJOR_MINOR, count=5, slave=slave_id)
+            # Grouped reads for efficiency
+            ir_valve = client.read_input_registers(REG_INPUT_VALVE_STATE_MOVEMENT, count=2, slave=slave_id)
+            ir_dig = client.read_input_registers(REG_INPUT_DIGITAL_INPUTS_STATE, count=2, slave=slave_id)
+            ir_sys = client.read_input_registers(REG_INPUT_FIRMWARE_VERSION_MAJOR_MINOR, count=5, slave=slave_id)
+            hr_valve = client.read_holding_registers(REG_HOLDING_MAX_OPENING_TIME_S, count=2, slave=slave_id)
+            hr_dig = client.read_holding_registers(REG_HOLDING_DIGITAL_OUTPUTS_STATE, count=1, slave=slave_id)
+            hr_sys = client.read_holding_registers(REG_HOLDING_WATCHDOG_TIMEOUT_S, count=1, slave=slave_id)
 
-            if rr.isError(): raise ModbusException(f"reading valve status: {rr}")
-            if hr.isError(): raise ModbusException(f"reading holding registers: {hr}")
-            if rr_sys.isError(): raise ModbusException(f"reading system status: {rr_sys}")
+            # Check for errors
+            for res in [ir_valve, ir_dig, ir_sys, hr_valve, hr_dig, hr_sys]:
+                if res.isError(): raise ModbusException(str(res))
 
-            valve_state_raw = rr.registers[0]
+            # --- Process Valve & Motor Data ---
+            valve_state_raw = ir_valve.registers[0]
             movement_map = {0: "Idle", 1: "Opening", 2: "Closing", 3: "Error"}
             state_map = {0: "Closed", 1: "Open"}
             new_data["movement"] = movement_map.get(valve_state_raw >> 8, 'Unknown')
             new_data["state"] = state_map.get(valve_state_raw & 0xFF, 'Unknown')
-            new_data["motor_current"] = f"{rr.registers[1]} mA"
-            new_data["open_time"] = f"{hr.registers[0]}s"
-            new_data["close_time"] = f"{hr.registers[1]}s"
+            new_data["motor_current"] = f"{ir_valve.registers[1]} mA"
+            new_data["open_time"] = f"{hr_valve.registers[0]}s"
+            new_data["close_time"] = f"{hr_valve.registers[1]}s"
 
-            fw_major = rr_sys.registers[0] >> 8
-            fw_minor = rr_sys.registers[0] & 0xFF
-            fw_patch = rr_sys.registers[1]
-            uptime_low = rr_sys.registers[3]
-            uptime_high = rr_sys.registers[4]
-            uptime_seconds = (uptime_high << 16) | uptime_low
+            # --- Process Digital I/O ---
+            new_data["digital_inputs"] = f"0x{ir_dig.registers[0]:04X}"
+            new_data["button_events"] = f"0x{ir_dig.registers[1]:04X}"
+            new_data["digital_outputs"] = f"0x{hr_dig.registers[0]:04X}"
+
+            # --- Process System Data ---
+            fw_major = ir_sys.registers[0] >> 8
+            fw_minor = ir_sys.registers[0] & 0xFF
+            fw_patch = ir_sys.registers[1]
+            uptime_seconds = (ir_sys.registers[4] << 16) | ir_sys.registers[3]
             new_data["firmware"] = f"v{fw_major}.{fw_minor}.{fw_patch}"
+            new_data["device_status"] = "OK" if ir_sys.registers[2] == 0 else "ERROR"
             new_data["uptime"] = format_uptime(uptime_seconds)
+            new_data["watchdog"] = f"{hr_sys.registers[0]}s"
 
         except ModbusException as e:
             new_data["error"] = f"Modbus Error: {e}"
@@ -94,7 +109,6 @@ def draw_button(stdscr, y, x, text, selected=False):
     """Draws a button with a border, handling selection highlight."""
     button_width = len(text) + 4
     color = curses.color_pair(2) if selected else curses.color_pair(1)
-
     stdscr.addstr(y, x, " " * button_width, color)
     stdscr.addstr(y, x + 2, text, color)
     stdscr.addstr(y - 1, x, "┌" + "─" * (button_width - 2) + "┐", color)
@@ -109,105 +123,90 @@ def main_menu(stdscr, slave_id):
     stdscr.nodelay(1)
     stdscr.timeout(100)
 
-    # --- Color Pairs ---
     curses.start_color()
-    curses.init_pair(1, curses.COLOR_WHITE, curses.COLOR_BLUE)  # Main: white on blue
-    curses.init_pair(2, curses.COLOR_BLUE, curses.COLOR_WHITE)  # Selected: blue on white
-    curses.init_pair(3, curses.COLOR_RED, curses.COLOR_BLUE)    # Error: red on blue
+    curses.init_pair(1, curses.COLOR_WHITE, curses.COLOR_BLUE)
+    curses.init_pair(2, curses.COLOR_BLUE, curses.COLOR_WHITE)
+    curses.init_pair(3, curses.COLOR_RED, curses.COLOR_BLUE)
     stdscr.bkgd(' ', curses.color_pair(1))
 
-    # --- UI State ---
-    menu = ["Open Valve", "Close Valve", "Stop Valve", "Set Max Opening Time", "Set Max Closing Time", "Exit"]
+    menu = ["Open Valve", "Close Valve", "Stop Valve", "Toggle Output 1", "Toggle Output 2", "Set Watchdog", "Firmware Update", "Exit"]
     current_row_idx = 0
-    
-    # State for transient messages
-    message = ""
-    message_time = 0
-    
-    # State for user input
-    input_mode = False
-    input_prompt = ""
-    input_str = ""
-    input_target_reg = 0
+    message, message_time = "", 0
+    input_mode, input_prompt, input_str, input_target_reg = False, "", "", 0
 
     while not stop_event.is_set():
         h, w = stdscr.getmaxyx()
-        
-        # --- Handle Input and State Changes ---
         key = stdscr.getch()
 
         if input_mode:
             if key in [10, 13]: # Enter
                 try:
-                    seconds = int(input_str)
-                    client.write_register(input_target_reg, seconds, slave=slave_id)
-                    message = f"-> Set time to {seconds}s"
-                except ValueError:
-                    message = "-> Invalid input. Please enter a number."
+                    value = int(input_str)
+                    client.write_register(input_target_reg, value, slave=slave_id)
+                    message = f"-> Set register 0x{input_target_reg:04X} to {value}"
                 except Exception as e:
                     message = f"-> Error: {e}"
-                message_time = time.time()
-                input_mode = False
-                input_str = ""
+                message_time, input_mode, input_str = time.time(), False, ""
             elif key == curses.KEY_BACKSPACE or key == 127:
                 input_str = input_str[:-1]
             elif key != -1 and chr(key).isprintable():
                 input_str += chr(key)
         else: # Navigation mode
-            if key == curses.KEY_UP and current_row_idx > 0:
-                current_row_idx -= 1
-            elif key == curses.KEY_DOWN and current_row_idx < len(menu) - 1:
-                current_row_idx += 1
+            if key == curses.KEY_UP: current_row_idx = (current_row_idx - 1) % len(menu)
+            elif key == curses.KEY_DOWN: current_row_idx = (current_row_idx + 1) % len(menu)
             elif key == curses.KEY_ENTER or key in [10, 13]:
                 selected_option = menu[current_row_idx]
-                message_time = time.time() # Set time for all actions
+                message_time = time.time()
 
-                if selected_option == "Exit":
-                    stop_event.set()
-                    continue
-                elif selected_option == "Open Valve":
-                    client.write_register(REG_HOLDING_VALVE_COMMAND, 1, slave=slave_id)
-                    message = "-> Sent OPEN command"
-                elif selected_option == "Close Valve":
-                    client.write_register(REG_HOLDING_VALVE_COMMAND, 2, slave=slave_id)
-                    message = "-> Sent CLOSE command"
-                elif selected_option == "Stop Valve":
-                    client.write_register(REG_HOLDING_VALVE_COMMAND, 0, slave=slave_id)
-                    message = "-> Sent STOP command"
-                elif "Set Max" in selected_option:
-                    input_mode = True
-                    input_prompt = f"Enter new value for '{selected_option}' (seconds): "
-                    input_target_reg = REG_HOLDING_MAX_OPENING_TIME_S if "Opening" in selected_option else REG_HOLDING_MAX_CLOSING_TIME_S
+                if selected_option == "Exit": stop_event.set(); continue
+                elif selected_option == "Open Valve": client.write_register(REG_HOLDING_VALVE_COMMAND, 1, slave=slave_id); message = "-> Sent OPEN command"
+                elif selected_option == "Close Valve": client.write_register(REG_HOLDING_VALVE_COMMAND, 2, slave=slave_id); message = "-> Sent CLOSE command"
+                elif selected_option == "Stop Valve": client.write_register(REG_HOLDING_VALVE_COMMAND, 0, slave=slave_id); message = "-> Sent STOP command"
+                elif "Toggle Output" in selected_option:
+                    bit = 0 if "1" in selected_option else 1
+                    try:
+                        current_val = client.read_holding_registers(REG_HOLDING_DIGITAL_OUTPUTS_STATE, count=1, slave=slave_id).registers[0]
+                        new_val = current_val ^ (1 << bit)
+                        client.write_register(REG_HOLDING_DIGITAL_OUTPUTS_STATE, new_val, slave=slave_id)
+                        message = f"-> Toggled Output {bit+1}"
+                    except Exception as e: message = f"-> Error: {e}"
+                elif selected_option == "Set Watchdog":
+                    input_mode, input_prompt, input_target_reg = True, "Enter Watchdog Timeout (s): ", REG_HOLDING_WATCHDOG_TIMEOUT_S
+                elif selected_option == "Firmware Update":
+                    message = "-> Firmware update process not yet implemented."
 
-        # --- Drawing Logic (Single Source of Truth) ---
         stdscr.clear()
-
-        # 1. Draw Status Area
-        with status_lock:
-            current_data = status_data.copy()
+        with status_lock: current_data = status_data.copy()
         
         if current_data.get("error"):
             stdscr.addstr(0, 0, current_data["error"], curses.color_pair(3) | curses.A_BOLD)
         else:
-            bold = curses.color_pair(1) | curses.A_BOLD
-            normal = curses.color_pair(1)
-            col1_x, col2_x, col3_x = 2, 35, 70
-            stdscr.addstr(1, col1_x, "Valve State:", bold); stdscr.addstr(1, col1_x + 14, str(current_data.get('state', 'N/A')), normal)
-            stdscr.addstr(2, col1_x, "Movement:", bold); stdscr.addstr(2, col1_x + 14, str(current_data.get('movement', 'N/A')), normal)
-            stdscr.addstr(3, col1_x, "Motor Current:", bold); stdscr.addstr(3, col1_x + 14, str(current_data.get('motor_current', 'N/A')), normal)
-            stdscr.addstr(1, col2_x, "Max Open Time:", bold); stdscr.addstr(1, col2_x + 16, str(current_data.get('open_time', 'N/A')), normal)
-            stdscr.addstr(2, col2_x, "Max Close Time:", bold); stdscr.addstr(2, col2_x + 16, str(current_data.get('close_time', 'N/A')), normal)
-            stdscr.addstr(1, col3_x, "Firmware:", bold); stdscr.addstr(1, col3_x + 11, str(current_data.get('firmware', 'N/A')), normal)
-            stdscr.addstr(2, col3_x, "Uptime:", bold); stdscr.addstr(2, col3_x + 11, str(current_data.get('uptime', 'N/A')), normal)
+            bold, normal = curses.color_pair(1) | curses.A_BOLD, curses.color_pair(1)
+            # Status Area
+            col1, col2, col3, col4 = 2, 30, 58, 88
+            stdscr.addstr(1, col1, "State:", bold); stdscr.addstr(1, col1 + 18, str(current_data.get('state', 'N/A')), normal)
+            stdscr.addstr(2, col1, "Movement:", bold); stdscr.addstr(2, col1 + 18, str(current_data.get('movement', 'N/A')), normal)
+            stdscr.addstr(3, col1, "Motor Current:", bold); stdscr.addstr(3, col1 + 18, str(current_data.get('motor_current', 'N/A')), normal)
+
+            stdscr.addstr(1, col2, "Digital Inputs:", bold); stdscr.addstr(1, col2 + 18, str(current_data.get('digital_inputs', 'N/A')), normal)
+            stdscr.addstr(2, col2, "Digital Outputs:", bold); stdscr.addstr(2, col2 + 18, str(current_data.get('digital_outputs', 'N/A')), normal)
+            stdscr.addstr(3, col2, "Button Events:", bold); stdscr.addstr(3, col2 + 18, str(current_data.get('button_events', 'N/A')), normal)
+
+            stdscr.addstr(1, col3, "Max Open Time:", bold); stdscr.addstr(1, col3 + 16, str(current_data.get('open_time', 'N/A')), normal)
+            stdscr.addstr(2, col3, "Max Close Time:", bold); stdscr.addstr(2, col3 + 16, str(current_data.get('close_time', 'N/A')), normal)
+            stdscr.addstr(3, col3, "Watchdog:", bold); stdscr.addstr(3, col3 + 16, str(current_data.get('watchdog', 'N/A')), normal)
+
+            stdscr.addstr(1, col4, "Firmware:", bold); stdscr.addstr(1, col4 + 12, str(current_data.get('firmware', 'N/A')), normal)
+            stdscr.addstr(2, col4, "Uptime:", bold); stdscr.addstr(2, col4 + 12, str(current_data.get('uptime', 'N/A')), normal)
+            stdscr.addstr(3, col4, "Device Status:", bold); stdscr.addstr(3, col4 + 12, str(current_data.get('device_status', 'N/A')), normal)
+        
         stdscr.addstr(5, 0, "─" * (w - 1), normal)
 
-        # 2. Draw Menu Buttons
         for idx, row in enumerate(menu):
             x = w // 2 - (len(row) + 4) // 2
             y = h // 2 - len(menu) + (idx * 3)
             draw_button(stdscr, y, x, row, idx == current_row_idx)
 
-        # 3. Draw Transient Message or Input Prompt
         if time.time() - message_time < 2.0:
             stdscr.addstr(h - 2, 0, message.ljust(w - 1), curses.color_pair(1) | curses.A_BOLD)
         
@@ -231,14 +230,10 @@ def main():
 
     client = ModbusSerialClient(port=args.port, baudrate=args.baud, stopbits=1, bytesize=8, parity="N", timeout=1)
     if not client.connect():
-        print(f"Error: Failed to connect to serial port {args.port}")
-        sys.exit(1)
+        print(f"Error: Failed to connect to serial port {args.port}"); sys.exit(1)
 
-    print(f"Successfully connected to {args.port}. Starting UI...")
-    time.sleep(0.5)
-
-    poll_thread = threading.Thread(target=poll_status, args=(args.slave_id, args.interval))
-    poll_thread.daemon = True
+    print("Successfully connected. Starting UI..."); time.sleep(0.5)
+    poll_thread = threading.Thread(target=poll_status, args=(args.slave_id, args.interval), daemon=True)
     poll_thread.start()
 
     try:
@@ -246,8 +241,7 @@ def main():
     finally:
         stop_event.set()
         print("\nExiting...")
-        if client.is_socket_open():
-            client.close()
+        if client.is_socket_open(): client.close()
         poll_thread.join(timeout=2)
 
 if __name__ == "__main__":